Current collector for electrically drivable vehicles for collecting direct current and alternating current

Abstract

The invention relates to a current collector (1) for electrically drivable vehicles for collecting direct current and alternating current, comprising a pantograph wearing strip system (9) which is arranged transversely to the direction of travel and which has both an AC pantograph slipper arrangement (A) for collecting alternating current and a DC pantograph slipper arrangement (D) for collecting direct current. The invention also relates to a current collector system and to an electrically drivable vehicle.

Description

[0001] Description

[0002] Current collectors for electrically powered vehicles for the collection of direct current and alternating current

[0003] The invention relates to a current collector for electrically powered vehicles for receiving direct current and alternating current, a current collector system and an electrically powered vehicle.

[0004] Recently, there has been demand for electric vehicles for overhead line operation, such as locomotives that can be powered by alternating current, direct current, and diesel. For electric operation, these vehicles are equipped with a pantograph.

[0005] The pantograph supplies power from an overhead contact line to electrically powered vehicles and is typically a high-voltage device. It is attached to the vehicle roof via the pantograph's base frame using support insulators. A pantograph is often constructed in the form of a contact strip system, which uses its contact points to establish direct contact with the overhead contact line.

[0006] A lifting mechanism located between the base frame and a lower arm is used to raise the pantograph and press it against the contact wire. A pressure-controlled air supply is provided for this purpose. The contact force is adjusted according to the relevant regulations, which depend on the type of overhead line.

[0007] Minor changes in the height of the contact wire are compensated for by a spring mechanism, while larger differences in the height of the contact wire during lowering (e.g. bridge crossings, tunnels, etc.) are accommodated by a scissor frame.

[0008] The pantograph is lowered by its own weight.

[0009] In a half-scissor pantograph design, the contact strip system is guided almost vertically by the scissor frame (geometrically a four-sided articulated joint). This vertical guidance means that the direction of travel has no influence on the contact force, making the pantograph equally suitable for both directions of travel.

[0010] There are already locomotives equipped with two or more different pantographs on their roofs, enabling operation with both direct current (DC) and alternating current (AC). It should be noted that pantographs for AC are designed differently than those for DC. For example, types SA AC1 b and SA AC3 b are used for AC, while types SA DC1 bC and SA DC2 bC are used for DC. These operate with different contact forces and have different coatings on their contact strips.

[0011] The limited space on a vehicle roof is problematic, especially when a diesel engine is involved. For example, there might not be room for a second pantograph on a vehicle because the entire roof area is already occupied by a pantograph and the exhaust system of a diesel engine. Furthermore, each additional pantograph incurs extra costs for purchase, installation, and maintenance.

[0012] It is an object of the present invention to provide a pantograph for electrically powered vehicles for receiving direct current and alternating current, a pantograph system and an electrically powered vehicle, with which the disadvantages described above are avoided, wherein the pantograph allows operation with direct current and alternating current.

[0013] This problem is solved by a current collector according to claim 1, a current collector system according to claim 9 and an electrically powered vehicle according to claim 11.

[0014] A current collector according to the invention for electrically powered vehicles serves to collect direct current and alternating current. It comprises a contact strip system arranged transversely to the direction of travel, which has both an AC contact strip arrangement for collecting alternating current and a DC contact strip arrangement for collecting direct current. The AC contact strip arrangement differs from the DC contact strip arrangement.

[0015] As mentioned in the introduction, the basic design of a current collector is known. In its pantograph configuration, for example on rail vehicles, it typically comprises a lower arm, an upper arm, a coupling rod, a parallel guide rod, a lifting mechanism, and a contact strip system (sometimes also referred to as a "scale" or "pallet") with a crossbar and contact strips (also referred to as "contact strips"). It is attached to the roof frame of a vehicle by (usually three) insulators. The contact strip system is arranged transversely to the direction of travel, i.e., essentially orthogonal to an overhead contact line, such as a catenary wire, to ensure a power supply while the vehicle is in motion. The invention relates to a current collector that incorporates a special contact strip system. Therefore, the following section will not discuss the design of a standard current collector in detail, but rather describe this particular contact strip system in more detail.

[0016] In contrast to normal slip ring systems, which have either slip rings for DC operation or slip rings for AC operation, the slip ring system according to the invention comprises both an AC slip ring arrangement for taking off alternating current and a DC slip ring arrangement for taking off direct current.

[0017] A "contact strip arrangement" refers to a parallel arrangement of several contact strips, roughly in a geometric arrangement similar to that currently seen on existing pantographs. This means, in particular, that the contact strips are all aligned with their centers on a single line and are perpendicular to this line, parallel to each other. This line preferably points in the intended direction of travel of a vehicle. Other elements, such as support elements, fastening elements, and a crossbar, can also be included in the contact strip arrangement; however, the contact strips are the essential elements for its function. A contact strip arrangement preferably comprises two contact strips.

[0018] The contact strip system according to the invention comprises two types of contact strips. These are, firstly, AC contact strips in an AC contact strip arrangement and, secondly, DC contact strips in a DC contact strip arrangement. At first glance, it might seem surprising that there should be differences between these, since only an electrical contact between the contact strip and the overhead line needs to be established. However, there are differences, for example, with regard to the coating of the contact strips. Firstly, it should be noted that their surface should be softer than that of the contact line, so that it wears down more slowly than the contact strips (since the latter can be replaced more easily). Secondly, it should be noted that the voltages in AC operation are generally higher than in DC operation. Therefore, higher currents generally flow in DC operation.The contact pressure is also generally higher in direct current operation than in alternating current operation. A typical coating for AC grinding wheels is graphite, while a typical coating for DC grinding wheels is metallized graphite or copper.

[0019] In short, the current collector according to the invention incorporates AC and DC contact strips in the contact strip system. For vehicle operation, this current collector should be combined with other functional components to form a current collector system. A current collector system according to the invention comprises a current collector as described in the invention, a measuring unit designed to measure the type of voltage applied to the current collector, and a switching unit designed to switch the current drawn from the current collector to AC contacts when the measuring unit indicates that an AC voltage is present at the current collector, and to DC contacts when the measuring unit indicates that a DC voltage is present at the current collector.

[0020] The current collector according to the invention is suitable for both direct current (DC) and alternating current (AC). However, very few motors are designed to operate with both types. They are generally either DC motors or AC motors. A DC motor can be operated with AC using a rectifier, and an AC motor can be operated with DC using an inverter.

[0021] In contrast to prior art vehicles, which have a separate pantograph for each type of current (i.e., direct current or alternating current) and are rigidly connected to a separate conversion element for operating the drive system, there is now only a single contact to the overhead line via the pantograph according to the invention. Therefore, for smooth operation, elements are required that can determine which type of current (direct current or alternating current) is supplied to the sliding contact and that direct the current to the appropriate conversion element.

[0022] In addition to the current collector, the current collector system according to the invention also includes the measuring unit and the switching unit.

[0023] The measuring unit is designed to measure the type of voltage applied to the current collector. This can be alternating current (AC) or direct current (DC). Suitable measuring devices are known in the art. Essentially, it only needs to be determined whether the voltage fluctuation is above a predefined threshold (AC) or below (DC). The measurement can be performed directly via the voltage or via a current. However, it should be noted that, as a rule, no current should yet be flowing to a vehicle's drive unit, since the measurement and proper current supply must be established first. Therefore, current can be measured, for example, using a measuring resistor.

[0024] The switching unit is designed to switch the current drawn from the current collector to AC contacts when the measuring unit indicates that an AC voltage is present at the current collector, and to DC contacts when the measuring unit indicates that a DC voltage is present at the current collector. Preferably, neither of these contacts is connected before a measurement, so that the wrong type of current cannot be mistakenly supplied to a drive unit before a measurement.

[0025] The states of the switching unit are therefore preferably the following:

[0026] - Before a measurement, after a switch-off signal, there is no contact with the current collector.

[0027] - After a measurement and detection of alternating voltage, the AC contact is connected to the current collector.

[0028] - After a measurement and detection of DC voltage, the DC contact is connected to the current collector.

[0029] Switching units can be implemented using relays or contactors.

[0030] An electrically powered vehicle according to the invention is, in particular, a locomotive. However, the invention is also suitable for trolleybuses or other vehicles that are electrically operated with an overhead line, e.g., a catenary wire.

[0031] The vehicle comprises a current collector system according to the invention and an electric drive system designed for operation with alternating current and direct current, and connected to the switching unit of the current collector system in such a way that it uses electrical energy from the current collector to drive the vehicle. The drive system can, for example, comprise a drive unit, in particular an electric motor, and conversion elements that convert the incoming direct and alternating current into the type of current (with the appropriate voltage) suitable for the drive unit. A direct current motor should always receive direct current in both operating modes (direct current and alternating current), and an alternating current motor only alternating current.

[0032] Further, particularly advantageous embodiments and developments of the invention are described in the dependent claims and the following description, wherein the claims of one claim category may also be further developed analogously to the claims and descriptions of another claim category, and in particular, individual features of different embodiments or variants may be combined to form new embodiments or variants. In a preferred current collector, the AC contact strip arrangement is arranged on a first contact strip carrier and the DC contact strip arrangement on a second contact strip carrier. The two contact strip arrangements are thus located side by side in a separate arrangement. It is preferred that the AC contact strip arrangement has a first override bracket and the DC contact strip arrangement has a second override bracket.Essentially, the contact strip system comprises two different contact strip systems, which (in side view) are arranged side by side or, viewed according to the intended direction of travel, one behind the other. The height of all contact strips should be the same so that they can all make contact with the overhead line simultaneously.

[0033] Preferably, the AC contact strips are mounted in such a way that a defined vertical movement within the contact strip system is possible, but tilting is prevented. The AC contact strips are mounted on non-linear springs whose spring force decreases after a predetermined maximum of the force acting upon them (e.g., 100 N or 80 N) or at least increases less than before reaching this maximum. This has the advantage that while the DC contact strips can be pressed against a contact line with a greater force, the force with which the AC contact strips are then pressed against the contact line is lower. This increases the service life of the AC contact strips.

[0034] In an alternative preferred current collector, the AC contact strip arrangement and the DC contact strip arrangement are mounted on a common contact strip carrier. This allows for more compact designs. It is preferred that the AC contact strip arrangement and the DC contact strip arrangement share a common override bracket. This also contributes to a more compact design.

[0035] Preferably, each grinding element arrangement comprises two grinding elements.

[0036] Regarding an arrangement on a common contact strip carrier, it is preferred that AC contact strips of the AC contact strip arrangement are arranged between DC contact strips of the DC contact strip arrangement. The contact strip arrangements thus overlap. Similarly, or additionally, DC contact strips of the DC contact strip arrangement can also be arranged between AC contact strips of the AC contact strip arrangement. It is particularly preferred that all DC contact strips are located between AC contact strips, or that all AC contact strips are located between DC contact strips, i.e., that one contact strip arrangement is located within another contact strip arrangement.

[0037] Alternatively, the AC and DC contact strips can also be arranged alternately. A preferred current collector is therefore characterized by the fact that the AC contact strips of the AC contact strip arrangement and the DC contact strips of the DC contact strip arrangement are arranged alternately.

[0038] Preferably, the grinding pieces of the AC grinding piece arrangement are coated with graphite, graphene or graphene oxide.

[0039] Preferably, the grinding pieces of the DC grinding piece arrangement are coated with metallized graphite, graphene, graphene oxide or copper.

[0040] A preferred pantograph is characterized by the inclusion of four or more insulators for mounting the pantograph to a vehicle's roof frame. The number of insulators can be determined based on weight and / or expected air resistance.

[0041] A preferred pantograph is designed for mounting on a rail vehicle, preferably a locomotive.

[0042] The contact force required to press a pantograph against an overhead line for DC operation typically differs from that required for AC operation. A preferred pantograph system, i.e., a combination of the pantograph with a measuring unit and a switching unit, is therefore designed for the automatic control and / or monitoring of the pantograph's contact force against the overhead line. The measuring unit can determine, upon electrical contact with the overhead line, whether DC or AC voltage is present and output this information. Based on this information, a lifting unit for the pantograph can determine the required contact pressure or set the contact force with which the pantograph should be pressed against the overhead line.In this context, it is preferred that a higher contact force is used for DC operation than for AC operation. Preferably, the contact force for AC operation is between 40 N and 120 N, more preferably between 60 N and 100 N, and particularly 80 N. Preferably, the contact force for DC operation is between 120 N and 200 N, more preferably between 140 N and 180 N, and particularly 160 N.

[0043] A preferred electrically powered vehicle is characterized by the fact that the drive system comprises an AC module, which converts incoming alternating current for a drive unit (of the drive system), and a DC module, which converts incoming direct current for the drive unit. The drive system thus comprises the drive unit, e.g., an electric motor, which serves to drive the wheels, and the AC and DC modules, which are conversion units and supply the drive unit with the appropriate current and voltage.

[0044] The DC module is connected to the DC contacts (of the switching element of the current collector system) and the AC module to the AC contacts.

[0045] Preferably, the DC module includes an inverter and / or a unit that increases or decreases a voltage (e.g., a controller or a transformer).

[0046] Preferably, the AC module includes a rectifier and / or a unit that increases or decreases a voltage (e.g., a controller or a transformer).

[0047] A preferred electrically driven vehicle comprises an adjustment unit designed to adjust the pantograph and press it against an overhead line with a predetermined contact force. Such lifting devices are known in the prior art and can press a pantograph against a contact line with a predetermined force. The vehicle according to the invention is designed such that the force with which the lifting device presses the pantograph against a contact line is predetermined by the measuring unit of the pantograph system, i.e., it occurs automatically based on a state of the pantograph system.

[0048] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They show:

[0049] Figure 1 shows a pantograph according to the prior art from the side,

[0050] Figure 2 shows a pantograph according to the prior art from the front,

[0051] Figure 3 shows a part of a pantograph according to the prior art from above,

[0052] Figure 4 shows a side view of a sanding strip system according to the invention.

[0053] Figure 5 shows another sliding strip system according to the invention from the side, Figure 6 shows a current collector system according to the invention from the side.

[0054] Figure 1 shows a side view of a pantograph 1 designed as a half-scissor mechanism, depicted here in a partially lowered position. The pantograph 1 is attached to the roof frame 3 of a vehicle (not shown) in a manner known per se via insulators 2. The half-scissor mechanism consists of the lower arm 4, two rigidly connected upper arms 5, the coupling rod 6, and the parallel guide rod 7. The linkage, which is articulated to one another, is adjusted by means of a pneumatic lifting device 8, whereby the contact strip system 9, which is articulated at the free end of the upper arms, can be adjusted vertically while maintaining its horizontal orientation and thus pressed against the contact wire (not shown).

[0055] The contact strip system 9 comprises two parallel contact strips 10 running transversely to the overhead contact line and a crossover bracket 12 positioned between them. Parts 10 and 12 are connected to each other by struts and form a rigid unit, which is detachably mounted on a contact strip support. The contact strip support is designed as an I-shaped linkage and has semi-shell-shaped support elements in cross-section into which the struts and the crossover bracket 12 can be inserted. The contact strip support is mounted on the upper arms 5 and the parallel guide rod 7 in such a way that it can be adjusted by pivoting while maintaining its horizontal position, as already described.

[0056] Figure 2 shows the pantograph of Figure 1 from the front and Figure 3 shows the part of the pantograph with the contact strip system 9 from the side.

[0057] Figure 4 shows a side view of a contact strip system 9 according to the invention. If the current collector 1 of Figure 1 were equipped with this system, a current collector 1 according to the invention would result. In the embodiment shown here, an AC contact strip assembly A is arranged on a first contact strip carrier T and a DC contact strip assembly D is arranged on a second contact strip carrier T. These two are connected to each other by means of rods S to form a rigid contact strip system 9. The AC contact strip assembly A has a first override bracket 12 and the DC contact strip assembly D has a second override bracket 12.

[0058] Figure 5 shows a further contact strip system 9 according to the invention from the side, with which the current collector 1 of Figure 1 could be converted into a current collector 1 according to the invention. In the embodiment shown here, the AC contact strip arrangement A and the DC contact strip arrangement D are arranged on a common contact strip carrier T and have a common override bracket 12. In the case shown here, the AC contact strips 10 of the AC contact strip arrangement A and the DC contact strips 11 of the DC contact strip arrangement D are arranged alternately. However, it is also quite possible for one contact strip arrangement to be located between the other contact strip arrangement.

[0059] Figure 6 shows a current collector system 13 according to the invention from the side.

[0060] The pantograph 1 is mounted on insulators 2 on the roof frame 3, which can be considered representative of a rail vehicle 3. Its basic structure is that of the pantograph according to Figure 1 combined with the contact strip system according to Figure 5. For reasons of stability, four or more insulators 2 could potentially be used to attach the pantograph 1 to a roof frame 3.

[0061] The current collector system 13 shown here comprises this current collector 1, a measuring unit 14 designed to measure the type of voltage applied to the current collector 1, and a switching unit 15 designed to switch the current drawn from the current collector 1 to AC contacts 16 when the measuring unit 14 indicates that an AC voltage is applied to the current collector 1, and to DC contacts 17 when the measuring unit 14 indicates that a DC voltage is applied to the current collector 1.

[0062] Thick arrows illustrate the current flow from the slip ring system 9 to the switching unit 15, with the first arrow pointing to an AC slip ring, indicating that alternating current is being tapped. The current type ("alternating current") has already been determined by the measuring unit 14, and the switching unit 15 has been connected accordingly to the AC contacts 16.

[0063] This figure essentially shows the essential functional elements of an electrically powered vehicle (the rail vehicle 3), namely the current collector system 13 and an electric drive system 18, 19, 20. The drive system 18, 19, 20 comprises an AC module 18, which converts incoming AC current for the drive unit 20, and a DC module 19, which also converts incoming DC current for the drive unit 20. The DC module 19 is connected to the DC contacts 17, and the AC module 18 to the AC contacts 16.

[0064] In this case, the AC contact 17 is switched by the switching unit 15, and the AC current from the AC sliding piece flows to the AC module 18, where it is converted to a suitable form for the drive unit 20 and used to drive the rail vehicle, as represented by the drive wheels 21. Finally, it should be noted again that the invention described in detail above represents only exemplary embodiments, which can be modified in various ways by those skilled in the art without departing from the scope of the invention. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times.

[0065] Similarly, terms like "unit" do not preclude the possibility that the components in question consist of several interacting sub-components, which may also be spatially distributed. The term "a number" should be read as "at least one." Regardless of the grammatical gender of a particular term, persons of male, female, or other gender identities are included.

[0066] Reference symbol list

[0067] 1 Current collector 2 Insulator

[0068] 3 Roof frame I Rail vehicle

[0069] 4 Forearm 5 Upper arm

[0070] 6 Coupling rod 7 Parallel guide rod

[0071] 8 Lifting device 9 Grinding strip system

[0072] 10 AC grinding piece

[0073] 11 DC grinding piece

[0074] 12 rollover bars

[0075] 13 Current collector system 14 Measuring unit 15 Switching unit 16 AC contact 17 DC contact

[0076] 18 AC module 19 DC module 20 Drive unit 21 Drive wheels A AC grinding wheel arrangement

[0077] D DC grinding piece arrangement S rod T grinding strip carrier

Claims

Patent claims 1. Current collector (1) for electrically powered vehicles for drawing direct current and alternating current, comprising a contact strip system (9) arranged transversely to the direction of travel, which has both an AC contact strip arrangement (A) for drawing alternating current and a DC contact strip arrangement (D) for drawing direct current, wherein the contact strips of the AC contact strip arrangement (A) and the contact strips of the DC contact strip arrangement (D) have the same height, so that all contact strips can be brought into contact with an overhead line simultaneously.

2. Current collector (1) according to claim 1, wherein the AC contact strip assembly (A) is arranged on a first contact strip carrier (T) and the DC contact strip assembly (D) is arranged on a second contact strip carrier (T), preferably wherein the AC contact strip assembly (A) has a first override bracket (12) and the DC contact strip assembly (D) has a second override bracket (12).

3. Current collector (1) according to claim 1, wherein the AC contact strip arrangement (A) and the DC contact strip arrangement (D) are arranged on a common contact strip carrier (T), preferably wherein the AC contact strip arrangement (A) and the DC contact strip arrangement (D) have a common override bracket (12).

4. Current collector (1) according to claim 3, wherein AC grinding pieces (10) of the AC grinding piece arrangement (A) are arranged between DC grinding pieces (11) of the DC grinding piece arrangement (D), and / or wherein DC grinding pieces (11) of the DC grinding piece arrangement (D) are arranged between AC grinding pieces (10) of the AC grinding piece arrangement (A).

5. Current collector (1) according to claim 3 or 4, wherein the AC contact strips (10) of the AC contact strip arrangement (A) and the DC contact strips (11) of the DC contact strip arrangement (D) are arranged alternately.

6. Current collector (1) according to one of the preceding claims, wherein the contact pieces of the AC contact piece arrangement (A) are coated with graphite, graphene or graphene oxide and / or wherein the contact pieces of the DC contact piece arrangement (A) are coated with metallized graphite, graphene, graphene oxide or copper.

7. Current collector (1) according to one of the preceding claims comprising four or more insulators (2) for attaching the current collector (1) to a roof frame (3) of a vehicle.

8. Current collector (1) according to one of the preceding claims designed for mounting on a rail vehicle (3), preferably a locomotive.

9. Current collector system (13) comprising a current collector (1) according to one of the preceding claims, a measuring unit (14) designed to measure the type of voltage applied to the current collector (1) and a switching unit (15) designed to switch the current drawn from the current collector (1) to AC contacts (16) when the measuring unit (14) indicates that an AC voltage is applied to the current collector (1) and to DC contacts (17) when the measuring unit (14) indicates that a DC voltage is applied to the current collector (1).

10. Current collector system (13) according to claim 9, designed for automatic control and / or monitoring of a contact force of the current collector (1) on an overhead line, preferably wherein a greater contact force is used for DC operation than for AC operation.

11. Electrically powered vehicle, in particular a locomotive, comprising a pantograph system (13) according to claim 9 or 10 and an electric drive system (18, 19, 20) designed for operation with alternating current and direct current and connected to the switching unit (15) of the pantograph system (13) in such a way that it uses electrical energy from the pantograph (1) to drive the vehicle.

12. Electrically propelled vehicle according to claim 11, wherein the drive system (18, 19, 20) comprises an AC module (18) which converts incoming AC current for a drive unit (20) of the drive system (18, 19, 20) and a DC module (19) which converts incoming DC current for the drive unit (20) and the DC module (19) is connected to the DC contacts (17) and the AC module (18) is connected to the AC contacts (16), preferably wherein the DC module (19) comprises an inverter and / or a unit which increases or decreases a voltage, and / or the AC module (18) comprises a rectifier and / or a unit which increases or decreases a voltage.

13. Electrically powered vehicle according to claim 11 or 12, comprising an adjustment unit designed to adjust the pantograph (1) and press it against an overhead line with a predetermined contact force, preferably automatically based on a state of the pantograph system (13).

Images